Cushioning means and method for mechanical joints



O. U. ZERK April 10, 1934.

CUSHIONING MEANS AND METHOD FOR MECHANICAL JOINTS Qrgnal Filed Oct. 24,1930 Ill/[Ill INVENTOR. f OQCaJLLU -Zlk ATTORNEYS Patented Apr. 10, 1934PATENT ol-Flclaz4 UNITED STATES oUsHIoNING MEANS AND ME'rnoD FonMECHANICAL JoIN'rs Oscar U. Zerk, Cleveland, Ohio 18 Claims. (Cl.267-54) bular type of rubber bushings consisting of concentricallytelescoped metal tubes, having tubes of rubber or other suitable elasticor resilient material interposed therebetween.

This general type of bushing has been well known for many years and hasbeen used for the purpose of entirely eliminating the necessity oflubrication for the so-called swivel bearings, having movement oflimited angularity such as shackle bearings, coupling bearings, andother of the various bearings used in an automobile, by inserting therubber bushing between the inner and outer members of the bearing, anddepending upcn the inherent load supporting and resilient properties ofthe rubber interposed between the bearing members, for load supportingand cushioning functions.

The customary way of placing the above type of rubber bushing in abearing consists of driving the assembled bushing tightly into the outerportion of a swivel bearing while the inside metal tube has to betightly connected with the bolt or the like forming the inner member ofthe bearing. The present way of connecting the inside metal tube with abolt is by using a third member such as a spring shackle to which thebolt is tightly connected and which third member is pressed against bothoutstanding ends of the inside metal tube.

It has been previously proposed to provide a rubber cushioningconstruction wherein fibre bushings, washers, or the like, areinterposed between the rubber or like bushing and the inner bolt, andhanger or shackle parts, to provide for relative rotation of the innerparts of the rubber cushioning element relative to said bolt andassociated parts. undesirable because they do not eliminate the need forlubrication.

Two types of rubber cushioning constructions are commonly employed whererubber bushings are used. In the flrst type, such as in the springshackles of an automobile, the rubber bushing is placed between twomembers which can be pressed longitudinally against the rubber bushing.

In-the other type, the rubber bushing driven into the outer portion ofthe bearing is placed in a relatively stiff yoke such as the springhanger ofman ,automobile frame. Since in such prior constructions it isnecessary that the projecting ends of the inner tube must be pressedagainst the yoke of the spring hanger in order Such constructions arevery,

to prevent the inner tube from revolving, this can be accomplished inthe spring hanger yoke construction only by bending the yoke, when screwpressure is applied at the centrally located bolt.

Since this pressure has to be made great in order to bend the verystift` yoke of the spring hanger it is only natural that the workmenassembling the joint, will in many cases not apply suiicient pressure tobend the spring hanger thinking that they may break the relatively smallbolt. Whenever this occurs the inside tube will not press with itsprojecting ends against the two sides of the yoke of the spring hanger,the inside tube will then, therefore, not be rigidly connected witheither the yoke or the bolt, and the tubular rubber portion of therubber bushing will become inoperative, with the entire rubber bushingacting substantially as a plain solid metal bushing. The inner metaltube in such a case will rotatively oscillate in bearing contact withthe bolt surface, or if friction between the inner surface of the innermetal tubing and the bolt is greater than the friction between the boltand the resultant two bearing surfaces in the yoke, the engaged surfacesof the bolt and yoke will move against each other under high pressure,and with no lubricant supplied to these moving members, they willquickly wear out, creating squeaking noises at all times.

In prior constructions multi-tubular cushioning elements have sometimesincluded intermediate rubber tubes either held in compressed ornon-compressed condition by the inner and outer metal tubes, wherein therubber tube is cemented to or vulcanized to the engaged surfaces of themetal tubes. My present invention in its different aspects contemplatesthe use either of rubber tubes held in compression, and vulcanized ornot as desired, or rubber tubes not held in compression but interlockedwith or cemented to the metal tubes, as by vulcanizing or the like.

An object of my invention is to provide an improved cushioning jointconstruction for mechanisms wherein such a joint may find anadvantageous use.

Another object of my invention is to provide an improved cushioningjoint to connect relatively slightly oscillatable parts of a mechanismwhich may be very expeditiously installed in assembled relation to theother parts of the mechanism.

Another object of my invention is to yprovide an improved cushioningjoint to connect relatively slightly oscillatable parts of a mechanismwhich will be very eiiicient and durable in use.

Another object of my invention is to provide an improved resilientcushioning joint for mechanisms wherein accurate machining of theelement of the mechanism which is disposed inwardly of my improvedcushioning element, per se, and a relatively telescoped tubular part ofthe joint, per se, may be dispensed with.

Another object of my invention is to provide an improved resilient jointbetween relatively slightly oscillatory parts of mechanisms, whose firstcost is low.

Another object of my invention is to provide an improved resilient jointbetween relatively slightly oscillatory parts of mechanisms, which maybe very inexpensively assembled into the mechanisms.

Another object of my invention is to provide an improved combinedresilient joint and support therefore whereby the joint is adapted torelatively interconnect a pair of relatively oscillatable parts of amechanism.

Another object of my invention is to provide improved means to join tworelatively oscillatable parts of a mechanism.

Another object of my invention is to provide an improved hangerconstruction including an improved bolt connector means forinterconnecting the eye of a leaf spring of an automotive vehicle to theframe thereof.

Another object of my invention is to provide an improved hanger andjoint means for connecting the eye of a spring of an automotive vehicelto the frame of the vehicle, whereby clamping pressure exerted upon theparts of the interconnecting means will not distort the arms of thehanger.

Other objects of my invention and the invention itself will be readilyapparent to those skilled in the art to which my invention appertains,by reference to the following description of certain embodiments of myinvention and which are illustrated in the accompanying drawing, ofwhich Fig. 1 is a transverse sectional view, and

Fig. 2 is a side elevational view of a spring hanger and cushioningjoint mechanism for interconnecting the eye of a vehicle spring with theframe of a vehicle, and which embodies principles of my invention;

Fig. 3 is a plan view of the hanger and joint means of Figs. 1 and 2;

Figs. 4 and 5 are transverse sectional views showing graphicallysuccessive positions of the parts involved in the apparatus of Figs. 1to 3 inclusive, during successive assembling operations preceding thefinal operation which causes the parts to assume the position shown inFigs. 1 to 3 inclusive;

Fig. 6 is a transverse sectional view, otherwise like that of Fig. 3 butshowing a variant embodiment of my invention;

Fig. '7 is a view otherwise like that of Figs. 1 and 6, but illustratinganother variant embodiment of my invention;

Fig. 8 is a section taken on the line 8-8 of Fig. 7;

Fig. 9 is a section taken on the line 9 9 of Fig. 1;

Fig. 10 is a section taken on the line 10-10 of Fig. 1;

In Fig. 9 a fragment only of the hanger per se is shown, and in Fig'. 10a view of the adjacent hanger parts is omitted.

Referring now to the embodiment of my inver!- tion illustrated in Figs.1 to 3 inclusive, and in Figs. 9 and 10, the cushioning element per seis shown therein in combination with a preferably one-piece springhanger 19 for an automobile spring suspension, the hanger having apreferably planular intermediate yoke portion 20, perforated at 21 and22 for the reception of bolts or rivets securing the hanger to the frameof an automobile or the like, with a pair of substantially parallelpendant flanges 23 and 24 which are both provided with axially alignedbores 25 and 26, the latter being of greatest diameter.

The assembled parts comprising the said hanger 19, and the leaf springeye 27, securing bolt 28 and cushioning element per se, and includingthe laterally disposed annular resilient spacers 29 and 30, are bestshown in Figs. 1 to 3 inclusive. Referring therefore more particularlyto Figs. 1 to 3 inclusive, the multi-tubular cushioning elementexclusive of the resilient annular spacers 29 and 30, comprising theinner preferably seamed metal tube 3, the intermediate rubber tube 5,and the outer relatively thin shorter metal tube 1, disposed relativelytelescoped in the order named, with the projecting ends in turntelescoped within the tubular eye 27 at the end of the vehicle leafspring with preferably the end edges of the outer tube 1 disposed flushrelative to the lateral edges of the spring eye, the rubber tube 5 beingpreferably of somewhat shorter length than the outer tube and tightlycompressed between the inner and outer metal tubes named, and with theinner seamed tube 3 having ends 4 projecting beyond the end edges of theouter tube and spring eye.

When the parts are in assembled relation the bolt 28 tightly clampsbetween the inner side of its enlarged head 31 and the inside face ofthe hanger arm 23 the spring eye with its contained multi-tubularcushioning element and withv the annular spacers 29 and 30 interposedbetween the lead 31 and the hanger arm ,23 and said spring eye andmulti-tubular cushioning element.

The arm 24 is not subjected to any of the clamping pressure, this beingeffected by the bolt 28 merely upon the cushioning element parts andspring eye and the hanger arm 23.

The surfaces of the hanger arm 23 and of the bolt head 311 whichdirectly engage the rubber spacers 29 and 30 during the clamping, asabove described, are preferably annularly serrated as shown at 32 and33, Figs. 9 and 10, to produce a substantially positive interlockbetween the indentured rubber spacers and the teeth effected by theserrations.

The rubber washers prevent longitudinal movements of the tubular outerportion of the mechanism and closing of the cushioning element relativeto the inner bolt and lateral arms of the shackles or hangers of themechanism. The washers also prevent the ingress of dust and dirt to theinterior parts of the cushioning element.

The inner longitudinally seamed tube 3 limits the clamping actioneifected by the bolt, since it is interposed between and operates tospace the inner face of the bolt head 31 and the inner face of thehanger arm 23 so that the clamping action force which is eifected by thebolt when the nut 16 is turned to home position is limited by the lengthof the inner cushioning element tube 3. Compression of the rubberspacers 29 and 30 will cause these spacers to ilow, to a limited degree,radially outwardly and longitudinally inwardly of the tube 3 to eifectabutting engagement between the end portions of the rubber tube 5 andinwardly projecting portions of the annular spacers.

'I'he parts illustrated in Figs. 1 to 3 are assembled in the manner bestillustrated in Figs. 4 and 5 taken in connection with Figs. l to 3inclusive, the latter showing the completely assembled apparatus.

Fig. 6 illustrates the-multi-tubular cushioning element per seconsisting of the relatively telescoped tubes 1, 5,and. 3 in assembledrelation disposed within the spring eye 27 and with the annular rubberspacers 6 partially telescoped onto the outwardly projecting ends 4 ofthe tube 3 against the end edges of the spring eye 27 and those of thetube 1, which are flush therewith.

The next step in the assembling operation is to project the spring eyewith the carried cushioning element parts as illustrated in Fig. 4,between the relatively widely spaced pendent arms 23 and 24 of thehanger 19, which can be readily accomplished without the necessity ofany forcing or compressing tools because of the wide spacing of the arms23 and 24. With the parts in the relative positions shown in Fig. 5, thebolt 28 is then projected threaded end first successively through thelarge opening 26 of the hanger arm 24, the annular spacer 30, the innermetal tube 3, the annular spacer 29, and the relatively small opening 25through the hanger arm 23. y

When this is accomplished the washer 34 and clamping nut 16' are turnedon the threads of the bolt until the enlarged head 3l of the boltpressing against the outer lateral surface of the spacer and the innerlateral surface of the hanger arm 23 presses against the annular spacer29, whereby both of the spacers will be compressed and reduced inthickness except that portions of the rubber will flow between the metaltubes 1 and 3 to abut or approximately abut the ends of the rubbercushioning tube 5 and rubber material will also flow readily to arestricted degree to slightly increase the outside diameter of therubber spacers 29 and 30, as illustrated in Fig. 1.

By the structure above described and the mode of operation peculiar tothe above described structure, it is possible to very readily andexpeditiously assemble the various parts of the tubular cushioningelement and including the laterally disposed rubber washers 29 and 30into a rigid hanger, whether the same is formed in one piece of pressedsheet.metal or a malleable iron casting, or the like.

A variation of the above described mode of operation involved in theassembly of the parts described may be readily effected because of thefact that the outside diameter of .the washers 29 and/or 30 is such asto permitthese washers to be readilyprojected into the enlarged aperture26 of the hanger arm24, being subsequently compressed by the inner faceof the head of the bolt whereupon, being shifted to a position betweensaid hanger arm and the cushioning element, it will expand radially toeffect an increase in its outside diameter, as shown in Figs. 1 to 3inelusive.

vIn prior constructions difficulty is had in assembling the parts of aresilient joint because the width of the outer and closing portion ofthe mechanism such as the eye of a vehicle spring,

.added to the thickness of the two non-com` pressed rubber washers aredimensionally greater than the spacing between the two arms of theU-shaped hanger, or the like.

Both at the factory, where the automotive vehicles or other apparatusare being assembled, and also at repair and service stations oftentimesthe special tools, necessary to compress the two rubber washers beforeassembling are not available. My improved construction requires nospecial tools other than the tools ordinarily had in any reasonablyequipped garage or service station.

With the parts in position as shown in Fig. l,V

the keying projection extending laterally from the enlarged bolt head 31will be seated Within the groove or notch 36 forming a part of theenlarged aperture 26 through the hanger arm 24, with the result that thebolt is non-rotatably held with respect to the hanger and this in turnassures that the tube 3 which is in ultimate assembled position isdisposed with its ends tightly pressed between the bolt head 31 and thehanger arm S3, also non-rotatable relative to the hanger. I alsocontemplate further restricting the tendency of the inner tube 3 torotate relative to-the bolt 28 by sometimes providing the bolt 28 witha. rib projection 12 intertted within a longitudinal groove of thepreferably seamed inner tube 3.

In the embodiment as illustrated in Figs. 1 to 5 inclusive, I sometimes,as a further feature of improvement, bevel the inner end edges of thehanger arms, as shown at 6l, the divergent surfaces thus providedserving as guides when the cushioning elements are inserted between thearms to facilitate ready insertion of such elements therebetween.

I also contemplate interlocking the inner surface of the bolt head, andthe opposing inner surface of the hanger arm 23, with the rubber washers29 and 30, by providing these inner opposing clamping surfaces withradial serrations substantially in the manner as provided for theshackles 8 and 9, as previously described.

However, I may sometimes rely upon the frictional contact of the tubewith the bolt as described, to prevent relative rotation of these parts,particularly since a seamed tube 3 may be inexpensively made havingrelatively thick walls as shown.

I contemplate also sometimes omitting the rubber spacers 29 and 30 asshown in Figs. 1 to 5 inclusive, and in such case, as illustrated inFigs. 6 and 7, the bolt head shown at 31' may be of relatively smallsize and need not be as thick as the projection 35' and serves to clampthe inner metal tube 3 of the cushioning element comprising said innermetal tube, the outer metal tube 1, and the intermediate compressedrubber tube 5, as previously described, and which is disposed within thespring eye 27, in the same manner. In such a case reliance is placedupon the rubber tube 5 to prevent lateral movements of the hanger 19with the bolt 28 and inner metal tube 3 relative to the spring eye 27and the relatively teles'coped outer metal tube 1 rigidly fittedtherein.

In both cases, however, it is to be noted that the clamping bolts exertno inwardly directed clamping pressure on the two hanger arms tending topress them inwardly, but the clamping pressure exerted by the bolts isdirected 'solely upon two sides of the one hanger arm 23 and 23', as thecase may be.

Figs. 7 and 8 illustrate the variant form of bolt and inner metal tube,wherein a longitudinally extending locking projection 12 integral withthe bolt 28" is combined in association with the keying projection 35"extending laterally from the bolt head 31" to prevent relative.

rotation ofthe split or at least interiorly longitudinally grooved innermetal tube 3 of the cushioning element.

In some of the following claims wherein I employ the term bolt head,and/or enlarged portion of a bolt, it is to be understood that Icontemplate these terms to include also washers which may be employed,tting against the bolt head and cooperating therewith in a manneranalogous to a thicker bolt head per se, and the claims containing suchterms are to be so construed.

Having thus described my invention applied vto different embodiments andin variant forms of structures I am aware that numerous and extensivedepartures may be made from the said embodiments, forms, and structures,but without departing from the spirit 'of my invention.

The present application is a division of my copending application,Serial No. 518,369, led February 26, 1931, and also my co-pendingapplication, Serial No. 490,905, led October 24, 1930.

I claim:

l. In a cushioning joint and support therefor comprising a hanger havingan intermediate yoke portion and a pair of spaced pendent arms, acushioning element, comprising a rubber tube, a substantially seamlessmetal outer tube and a longitudinally seamed inner metal tube telescopedover and within said rubber tube respectively and exerting radiallydirected compressive stress on the rubber tube, and a bolt innonrotative relationship with the hanger for securing the cushioningelement to the hanger, said bolt clamping said cushioning elementsubstantially rigidly against said hanger and exerting pressure againstat least one of the ends of the inner metal tube of the cushioningelement without exerting deforming pressure upon the hanger arms.

2. In a cushioning joint and support therefor comprising a hanger havingan intermediate yoke portion and a pair of spaced pendent arms, acushioning element, comprising a rubber tube, a substantially seamlessmetal outer tube and a longitudinally seamed inner metal tube telescopedover and. within said rubber tube respectively and exerting radiallydirected compressive stress on the rubber tube, and a bolt for securingthe cushioning element to the hanger, said bolt in non-rotativerelationship with the hanger clamping said cushioning elementsubstantially rigidly against said hanger and exerting pressure againstatleast one of the ends of the inner metal tube of the`cushioningelement without exerting deforming pressure upon the hanger arms, and avehicle spring eye telescoped over and tted rigidly on the outer tube ofthe cushioning element, each of the tubes of said cushioning elementbeing of a length less than the distance between the hanger arms,whereby said cushioning element may be readily placed between said armsfor securing the cushioning element to the hanger.

3. The combination of a substantially U- shaped hanger, an element ofmechanism having an opening therethrough, a cushioning element tightlytted within said opening comprising a rubber tube, a substantiallyseamless metal outer tube anda longitudinally seamed inner metal tubetelescped over and within said rubber tube respectively and exertingradially directed compressive stress on the rubber tube, a pair ofresilient washers each placed on a dierent end of the seamed tube andadjacent the end of the rubber tube, a bolt slidably mounted within onearm of the hanger and exerting clamping pressure upon the cushioningelement and the other arm to compress the two resilient washersrespectively between the head of the bolt and one end of said cushioningelement and the said other arm and the other end of said cushioningelement.

4. In combination with a pair of mechanism parts, a tubular cushioningelement adapted to resiliently join the parts one of said parts having atubular opening therethrough `and within which the said cushioningelement is closely fitted, said other part comprising a pair oflaterally spaced arms adapted to embrace the ends of said cushioningelement when it is disposed within said other part opening, saidcushioning element comprising resilient annular ends, and a bolt adaptedto be projected through both of the arms of the said hanger and innon-rotative relationship therewith and to clamp the said cushioningelement together with its resilient ends onto one only of said arms tocompress it radially and axially, said bolt restrained from lateralmovements by the other said arm.

5. In combination with a pair of mechanism parts, a tubular cushioningelement adapted to resiliently join the parts, one of said parts havinga tubular opening therethrough and within which the said cushioningelement is lclosely fitted, said other part comprising a pair oflaterally spaced arms adapted to embrace the ends of said cushioningelement when it is disposed within said other part opening, each of saidarms perforated to provide concentrically aligned openings, a boltadapted to be projected successively through said openings andmaintained in non-rotative relation to the said arms, said bolt having aradially extending enlarged portion near an end, and a rubber washeradapted to be interposed between an end of said cushioning element andan inner face of the said enlarged portion of said bolt, the outsidediameter of said washer being normally of such a dimension as to permitthe washer being projected through an adjacent arm opening, said boltenlargement adapted to engage and compress said washer to expand it indiameter and to decrease its thickness by lateral pressure exerted bysaid bolt and cushioning element.

6. In combination with a pair of mechanism parts, a tubular cushioningelement adapted to resiliently join the parts, one of said parts havinga tubular opening therethrough and within which the said cushioningelement is closely itted, said other part comprising a pair of laterallyspaced arms adapted to embrace the ends of said cushioning element whenit is disposed within said other part opening, each of said armsperforated to provide concentrically aligned openings, a bolt adapted tobe projected successively through said openings and maintained innon-'rotative relation to said arms, said bolt having a radiallyextending enlarged portion near an end, and a rubber washer adapted tobe interposed between an end of said cushioning element and aninner faceof the said enlarged portion of said bolt, the outside diameter of saidwasherv being normally of such a dimension as to permit the washer beingprojected through an adjacent arm opening, said bolt enlargement adaptedto engage and compress said washer to expand it in diameter and todecrease its thickness by lateral pressure exerted by said bolt andcushioning element, one of said mechanism parts being in the form of aU-shaped hanger, said arms being integrally formed with the intermediateyoke portion thereof.

7. Incombination with a pair of mechanism parts, a tubular cushioningelement adapted to resiliently join the parts, one of said parts havinga tubular opening therethrough and within which the said cushioningelement is closely ntted, said other part comprising a pair of laterallyspaced arms adapted to embrace the ends of said cushioning element whenit is disposed within said other part opening, each of said armsperforated to provide concentrically aligned openings, a bolt adapted tobe projected successively through said openings, said bolt having aradially extending enlarged portion near an end, and a rubber Washeradapted to be interposed between an end of said cushioning element andan inner face of the said enlarged portion of said bolt, the outsidediameter of said washer being normally of such a dimension as to permitthe washer being projected through an adjacent arm opening, said boltenlargement adapted to engage and compress said washer to expand it indiameter and to decrease its thickness by lateral pressure exerted bysaid bolt and cushioning element, one of said mechanism parts being inthe form of a U-shaped hanger, said arms being integrally formed withthe intermediate yoke portion thereof, and means associated with saidbolt and the hanger arm having the said enlarged opening to interlockthe bolt with said arm to prevent rotation of the bolt relative to thearm, said interlocking means comprising a projection of the one receivedwithin a depression of the other.

8. In combination with la pair of mechanism parts, a tubular cushioningelement adapted to resiliently join the parts, one of -said parts havinga tubular opening therethrough and within which the said cushioningelement is closely fitted, said other part comprising a pair oflaterally spaced arms adapted to embrace the ends of said cushioningelement when it is disposed within said other part opening, each of saidarms perforated to provide concentrically aligned openings, a boltadapted to be projected successively through said openings, said bolthaving a radially extending enlarged portion near an end, and a rubberWasher adapted to be interposed between an end of said cushioningelement and an inner face of the said enlarged portion of said bolt, theoutside diameter of said washer being normally of such a dimension as topermit the washer being projected through an adjacent arm opening, saidbolt enlargement adapted to engage and compress said washer to expand itin diameter and to decrease its thickness by lateral pressure exerted bysaid bolt and cushioning element, one of said mechanism parts being inthe form of a U- shaped hanger, said arms being integrally `formed withthe intermediate yoke portion thereof, said bolt enlargement forming ahead for the bolt, said head comprising a laterally extendingprojection, the portion of the head having the projection adapted fordisposition within the said enlarged opening of said arm and extendinglaterally into a groove extension of said opening.

9. In a cushioning joint for relatively oscillatable mechanism parts,one of said parts comprising a pair ofl laterally spaced arms, aclamping bolt non-rotatively engaging at least one of said arms, theother of said parts having a tubular opening therethrough, a tubularcushioning element fitted tightly Within said opening, said cush ioningelement comprising an intermediateV rubber tube, and inner and outermetal tubes telescoped respectively within and outside of said rubbertube, said clamping bolt adapted to tightly clamp said inner tuberigidly to at least one of said arms, said inner tube having alongitudinal seam and a wall thickness which is substantially greaterthan the wall thickness of the outer tube.

10. In a cushioning joint for relatively oscillatable mechanism parts,one of said parts comprising a pair of laterally spaced arms, a clampingbolt non-rotatively engaging at least one of said arms, the other ofsaid parts having a tubular opening therethrough, a tubular cushioningelement fitted tightly within said opening, said cushioning elementcomprising an intermediate rubber tube, and inner and outer metal tubestelescoped respectively within and outside of said rubber tube, saidclamping bolt adapted to tightly clamp said inner tube rigidly to one ofsaid arms, said inner tube having a longitudinal seam and a wallthickness which is substantially greater than the wall thickness of theouter tube, said bolt making bearing contact only with the other arm.

1l. In a cushioning joint for relatively oscillatable mechanism parts,one of said parts comprising a pair of laterally spaced arms, a clampingbolt non-rotatively engaging at least one of said 105 arms, the other ofsaid parts having a tubular opening therethrough, a tubular cushioningelement fitted tightly within said opening, said cushioning elementcomprising an intermediate rubber'tube, and inner and outer metal tubestelescoped respectively within and outside of said rubber tube, saidclamping bolt adapted to tightly clamp said inner tube rigidly to one ofsaid arms, a rubber annulus interposed between said cush- Oning elementand the said arm to which the cushioning element is clamped whereby theclamping bolt may compress the washer and the rubber tube axially andradially.

12. In a cushioning joint for relatively oscillatable mechanism parts,one of said parts comprising a pair of laterally spaced arms, vaclamping bolt non-rotatively engaging at least one of said arms, theother of said parts having a tubular opening therethrough, a tubularcushioning element iitted tightly within said opening, said cushioningelement comprising an intermediate rubber tube, and inner and outermetal tubes telescoped respectively Within and outside of said rubbertube, said clamping bolt adapted to tightly clamp said inner tuberigidly to one of said arms, a rubber annulus interposed between saidcushioning element and the said arm to which the cushioning element isclamped, the inner surface of said lastnamed arm being indentured withthe contacting surface of said Washer.

13. In a mechanical joint connector, in combination with a hanger andthe eye of a leaf spring, a bolt non-rotatively extending -between thearms of the hanger and adapted to clamp the leaf spring to one of thearms of the hanger only, and 140 cushioning means interconnecting saidbolt and leaf spring eye adapted to be compressed axially and radiallyby said clamp bolt to permit slight oscillatory relative movements ofthe bolt and eye.

14. In a mechanical joint connector, in combil leaf spring eye adaptedto be compressed axially and radially by said clamp bolt to permitslight oscillatory relative movements thereof, said cushioning meanscomprising a rubber spacing element.

15. In a mechanical joint connector, in combination with a hanger andthe eye of a leaf spring, a bolt non-rotatively extending between thearms of the hanger and adapted to clamp the leaf spring to one of thearms of the hanger only, the two ends of the bolt engaging relativelythe two arms of the hanger, the bolt head being supported and guidedlongitudinally only by said hanger and a cushioning element compressedaxially and radially by the bolt interposed between the bolt and thespring eye.

16. In a spring joint mechanism, the combination with a pair oflaterally spaced supports, a bolt, and the eye of a leaf spring, of atubular cushioning element fitted tightly Within the leaf spring eyecomprising a rubber tube, a substantially seamless metal outer tube anda radiallyl expansible inner metal tube telescoped over and within saidrubber tube respectively and exerting radially directed compressivestress on the rubber tube, said inner tube having substantially thickerwalls than the relatively thinner outer tube, said bolt extendingthrough the said inner tube and said supports compressing said innertube tightly against at least one of the supports, said bolt comprisinga keying projection extending into at least a portion of the seam of theinner tube, to restrain relative rotation of said tube and bolt.

17. In a spring joint mechanism, the combination with a pair oflaterally spaced supports, a bolt, and the eye of a leaf spring, of atubular cushioning element iltted tightly within the leaf spring eyecomprising a rubber tube, a substantially seamless metal outer tube anda radially expansible inner metal tube, which is longer than said outertube, telescoped over and Within said rubber tube respectively andexerting radially directed compressive stress on the rubber tube, saidbolt extending through the said inner tube and said supports compressingsaid inner tube tightly against at least one of the supports, said boltcomprising a keying projection extending into at least a portion of theseam of the inner tube, to restrain relative rotation of said tube andbolt.

18. In a spring joint mechanism, the combination with a pair oflaterally spaced supports, a bolt, and the eye of a leaf spring, of atubular cushioning element tted tightly Within the leaf spring eyecomprising a rubber tube, a substantially seamless metal outer tube anda radially expansible inner metal tube telescoped over and within saidrubber tube respectively, and exerting radially directed compressivestress on the rubber tube, said bolt extending through the said innertube and said supports, and non-rotative relative to the supports andcompressing said inner tube tightly against at least one of thesupports, said bolt comprising a keying projection extending into thematerial of the inner tube to restrain relative rotation of the saidtube and bolt.

OSCAR U. ZERK.

